IEC TS 60079-46:2017

IEC TS 60079-46 ®
Edition 1.0 2017-08
TECHNICAL
SPECIFICATION
Explosive atmospheres –
Part 46: Equipment assemblies
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IEC TS 60079-46 ®
Edition 1.0 2017-08
TECHNICAL
SPECIFICATION
Explosive atmospheres –
Part 46: Equipment assemblies
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 29.260.20 ISBN 978-2-8322-4763-1

– 2 – IEC TS 60079-46:2017 © IEC 2017
CONTENTS
FOREWORD . 3
INTRODUCTION . 5
1 Scope . 6
2 Normative references . 7
3 Terms and definitions . 7
4 General requirements for equipment assemblies . 8
4.1 General specifications . 8
4.2 Explosion protection specifications . 8
4.3 Hazardous area classification related to the equipment assembly . 8
4.3.1 General . 8
4.3.2 Equipment assembly with its own source of release . 9
4.4 Competencies . 9
5 Design of equipment assemblies . 9
5.1 General . 9
5.2 Ex Equipment . 9
5.2.1 Individual items . 9
5.2.2 Specific Conditions of Use as specified on certificates . 10
5.2.3 Item list . 10
5.3 Other items . 10
5.4 Wiring system . 10
5.5 Drawings. 11
6 Construction and assembly . 11
6.1 General . 11
6.2 Disassembly and reassembly . 11
6.3 System interfaces . 12
6.4 Ignition hazard assessment . 12
6.5 Calculations . 12
6.6 Inspection & testing . 12
6.7 Validation and documentation . 13
6.7.1 General . 13
6.7.2 Other material specifications . 14
6.7.3 Schedule Documents . 14
6.8 Instructions . 14
7 Certificate . 14
8 Marking . 15
8.1 General . 15
8.2 Determining Group marking . 15
8.3 Determining temperature class or maximum surface temperature marking . 16
8.4 Determining Equipment Protection Level (EPL) marking. 16
8.5 Determining ambient temperature range marking . 16
8.6 Determining ingress protection (IP Code) rating . 16

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
EXPLOSIVE ATMOSPHERES –
Part 46: Equipment assemblies
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
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with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
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5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
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6) All users should ensure that they have the latest edition of this publication.
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8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
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9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
The main task of IEC technical committees is to prepare International Standards. In
exceptional circumstances, a technical committee may propose the publication of a technical
specification when
• the required support cannot be obtained for the publication of an International Standard,
despite repeated efforts, or
• the subject is still under technical development or where, for any other reason, there is the
future but no immediate possibility of an agreement on an International Standard.
Technical specifications are subject to review within three years of publication to decide
whether they can be transformed into International Standards.
IEC TS 60079-46, which is a technical specification, has been prepared by IEC technical
committee TC 31: Equipment for explosive atmospheres.

– 4 – IEC TS 60079-46:2017 © IEC 2017
The text of this technical specification is based on the following documents:
Enquiry draft Report on voting
31/1312/DTS 31/1327/RVDTS
Full information on the voting for the approval of this technical specification can be found in
the report on voting indicated in the above table.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all parts in the IEC 60079 series, published under the general title Explosive
atmospheres, can be found on the IEC website.
The committee has decided that the contents of this publication will remain unchanged until
the stability date indicated on the IEC website under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication will be
• transformed into an International standard,
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
A bilingual version of this publication may be issued at a later date.

INTRODUCTION
The provision of products into end markets for installation by end users may take the form of
either individual items of equipment or pre-manufactured assemblies comprising many items
of equipment. Pre-manufactured equipment assemblies may be as either subsystems
requiring integration as part of an installation at a site or complete functional machines which
require little or no additional reassembly on site.
This document is applied when assembly of Ex Equipment(s) results in an assembly that
creates a need for additional assessment that is not already completely covered by the
individual equipment certificates. Additional assessment might include (but is not limited to)
evaluation of wiring methods used to connect the equipment(s) or temperature rise within the
assembly.
This document provides requirements for the design, construction, assembly, testing,
inspection, marking, documenting and assessment of equipment assemblies such that the
items of Ex Equipment and the interc
...